It's a tough set of tradeoffs. Chrome has more features here and there but (for example) the Firefox profiler gives MUCH more detailed and useful information if

It's a tough set of tradeoffs. Chrome has more features here and there but (for example) the Firefox profiler gives MUCH more detailed and useful information if your goal is to figure out where your CPU time is going. The chrome profiler is also incredibly slow, I suspect because the Chrome dev team rarely uses it and hasn't had to optimize it (they have a different profile viewer for things like tracing browser execution). The FF profiler is the main one the FF dev team uses, so in practice it's much faster. For that reason also it has profile sharing built in, which is handy.